Field of the Invention
The present invention relates to golf balls. Specifically, the present invention relates to golf balls that include a core, a mid layer, and a cover.
Description of the Related Art
Golf players' foremost requirement for golf balls is high flight distance performance. In particular, golf players place importance on high flight distance performance upon a shot with a driver. High flight distance performance correlates with the resilience performance of a golf ball. When a golf ball having excellent resilience performance is hit, the golf ball flies at a high speed, thereby achieving a large flight distance.
An appropriate trajectory height is required in order to achieve a large flight distance. A trajectory height depends on a spin rate and a launch angle. With a golf ball that achieves a high trajectory by a high spin rate, a flight distance is insufficient. With a golf ball that achieves a high trajectory by a high launch angle, a large flight distance is obtained. In light of flight distance, a low spin rate and a high launch angle are preferred.
Golf players also place importance on spin performance of golf balls. When a backspin rate is high, the run is short. It is easy for golf players to cause a golf ball, to which backspin is easily provided, to stop at a target point. When a sidespin rate is high, the golf ball tends to curve. It is easy for golf players to intentionally cause a golf ball, to which sidespin is easily provided, to curve. A golf ball to which spin is easily provided has excellent approach performance. In particular, advanced golf players place importance on approach performance upon a shot with a short iron.
Golf players are further interested in feel at impact of golf balls. A hard cover deteriorates feel at impact. Golf players prefer soft feel at impact.
In light of achievement of various performance characteristics, golf balls each having a multilayer structure have been proposed. JP2009-95365 discloses a golf ball that includes an inner envelope layer, an outer envelope layer, a mid layer, and a cover. The mid layer is harder than the inner envelope layer, the outer envelope layer, and the cover. JP2008-149131 (US2008/0146376) also discloses a similar golf ball. U.S. Pat. No. 6,152,834 discloses a golf ball that includes a core and a cover composed of at least three layers. In the golf ball, a soft and thick cover is formed as an outermost layer.
When a golf ball having a high launch angle and a low spin rate is hit with a driver, a large flight distance is obtained. However, a golf ball having a low spin rate has inferior approach performance. In recently years, golf players' requirements for golf balls have been escalated more than ever. A golf ball that achieves both a large flight distance and excellent approach performance on a high level is desired. Furthermore, a golf ball having soft feel at impact upon a shot is desired.
An object of the present invention is to provide a golf ball that has high flight distance performance upon a shot with a driver and excellent approach performance upon a shot with a short iron, provides favorable feel at impact, and has good durability.